1. Field of the Invention
This invention relates generally to methods and apparatus for containing and recovering oil spills and the like, and more particularly to the use of fibrous woven or non-woven fabric structures having water repellent and oil absorbent qualities for absorbing, containing, and recovering water-insoluble liquids, such as fuels, petroleum products, oil, etc.
2. Brief Description of the Prior Art
The containment and recovery of petroleum products, particularly oil spills at sea is a very serious problem which often results in contamination of miles of shoreline and damage to wildlife and natural flora and fauna.
Currently, several methods are used to clean-up such spills. Surfactants have been applied to the oil which reduces its surface tension, but the oil is merely dispersed and spread in a diluted form by sea currents. Absorbent materials which are heavier than water have been used, but sink to the bottom carrying a portion of the oil with it. These methods result in the risk of spreading the damage over a greater distance.
Mechanical methods have also been used, such as booms which float on the surface of the water to encircle and contain the spill until it can be collected by pumps and skimmers which remove the oil off the surface of the water. The mechanical methods are time consuming and not efficient and their effectiveness and reliability is further reduced by turbulent seas.
Microorganisms have recently been employed in oil spill clean-ups wherein the microorganism will "digest" the oil. This is presently an experimental method and the long-term effects of the microorganisms are uncertain.
On land, such methods as washing or steam cleaning the beaches and rocks have been used. This method is time consuming, labor intensive, costly, and for the most part is ineffective.
In industries such as manufacturing plants, and refineries, leakage from pipes, valves, or machinery is a common problem. The spilled or leaked liquid presents a safety problem and often results in costly down-time.
Ceaser, U.S. Pat. No. 4,780,518 discloses an oil absorbent, water-repellent polymeric carbohydrate composition made from a number of the hydroxyl groups of carbohydrate moieties reacted with a metal/ammonium complex. The fibrous composition, in a granulated or shredded form, may be used for oil spills wherein the fibers are assembled as a mass on water with the aid of a floating boom and guided toward the floating liquid to be absorbed.
Clark et al, U.S. Pat. No. 4,615,739 discloses a water sealant chemical composition in the form of a paint, stain, or clear coating used as a waterproof coating.
The present invention is distinguished over the prior art in general, and these patents in particular by an apparatus and method for containment and recovery of water-insoluble liquids, e.g., oil, floating on water which involves using a fibrous material coated or saturated with a composition which will absorb substantial quantities of the water-insoluble organic liquid (oil) while substantially repelling the water in which the water-insoluble organic liquid is floating. The fibrous material may be a fabric, a paper, a sponge, a sheet or a film and is coated or impregnated with an oleophylic, hydrophobic composition. Such materials as cotton, jute, hemp, wool, Rayon, Dacron, paper, polyester, and polyurethane, in various forms and combinations may be used. The composition is preferably an oil-in-water coating composition comprising an oil soluble resin or drying oil with an aqueous discontinuous phase dispersed therein, the discontinuous phase comprising an emulsion of a water insoluble resin, which coating composition passes or absorbs the water-insoluble liquid but repels water. The fibrous material impregnated or coated with an oleophylic, hydrophobic composition is passed into contact with the water-insoluble liquid (e.g. oil) whereupon the oil is absorbed and the water rejected. The oil-saturated material is recovered and the oil recovered therefrom and the fibrous material reused; reimpregnating the material with the oleophylic, hydrophobic composition, if necessary. The treated materials may also be used in industrial applications wherein the material to be absorbed does not float on water.